Question

For samples with the same mass, which kind of substance needs more energy to undergo an increase of \(5^{\circ} \mathrm{C},\) something with a large specific heat or something with a small specific heat? Explain.

Short answer

A substance with a large specific heat requires more energy for a 5°C temperature increase.

Step-by-step solution

Understanding Specific Heat

Specific heat capacity is the amount of heat energy required to raise the temperature of a substance per unit of mass. A substance with a high specific heat capacity requires more energy to increase its temperature compared to a substance with a low specific heat capacity.

Analyzing Temperature Change

When comparing two substances of the same mass undergoing the same temperature change, the one with the larger specific heat will need more energy to achieve this change.

Conclusion

A substance with a large specific heat needs more energy to undergo an increase of temperature by 5 degrees Celsius compared to a substance with a small specific heat.

Key concepts

Heat Energy

Heat energy, often just called 'heat,' is a form of energy transfer among particles in a substance (or between two substances) due to a temperature difference.

It's the energy you feel emanating from a hot stovetop or the warmth from the sun on your face. This energy flow stops when a common temperature is reached, showing that temperature is a measure of the average kinetic energy (movement) of particles in a substance.

Understanding Heat Transfer

When discussing heat transfer, we refer to three primary methods: conduction, convection, and radiation. By understanding these mechanisms, students can grasp how heat energy affects temperature changes in substances.

• Conduction: Movement of heat through a material without the movement of the material itself.
• Convection: Heat is transferred through fluids (liquids or gases) by the movement of currents within the fluid.
• Radiation: Transfer of energy by electromagnetic waves, which can occur in a vacuum and doesn't require a medium.

Temperature Change

Temperature change is a variation in the degree of hotness or coldness of a substance and indicates the direction of heat transfer; from a warmer body to a cooler one until equilibrium is reached.

An important tool to measure this in science is the Celsius scale, typically used in most of the world outside of the United States. In the exercise involving specific heat capacity, the temperature change of a sample is given as a 5-degree Celsius increase.

Calculating Temperature Differences

It's crucial to understand how to apply this to real-world situations. For example, if a tea kettle starts at room temperature, around 22 degrees Celsius, and is heated until it's 100 degrees Celsius, this is a temperature change of 78 degrees Celsius. Scientists and engineers use these calculations to design systems that manage thermal energy effectively.

Thermal Properties

Thermal properties of materials are parameters that define how a substance absorbs, stores, and transmits heat energy. One primary thermal property is specific heat capacity, which is central to the problem at hand.

In the context of the exercise, specific heat capacity translates to how much energy is required to change the temperature of a given mass of a substance by 1 degree Celsius. Different substances defy uniformity; water, for instance, has a high specific heat capacity, taking much more energy to heat than iron, which has a low specific heat capacity.

Importance in Everyday Applications

Considering thermal properties is fundamental in applications such as designing heating systems, improving energy efficiency, and even in culinary arts to determine the right cooking temperatures and times. By learning about thermal properties, students can better understand the energy requirements of different substances and the principles of keeping our homes warm or cooling electronic devices.